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EXPERIMENTAL STUDY OF INFLUENCE OF SLIGHT DEVIATION FROM ADSORPTION ISOTHERMS LINEARITY ON ELUTION PEAK PROFILESстатья
Информация о цитировании статьи получена из
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Дата последнего поиска статьи во внешних источниках: 26 декабря 2018 г.
- Автор: Larin A.V.
- Журнал: Journal of Chemical Engineering of Japan
- Том: 28
- Номер: 6
- Год издания: 1995
- Издательство: Society of Chemical Engineers Japan
- Местоположение издательства: Japan
- Первая страница: 851
- Последняя страница: 853
- Аннотация: An adsorption isotherm is the major factor affecting the peak profiles under conditions of hihgh performance chromatography). It mas repeadly enphasized that peak profiles in high-performance chromatography depend on concentation region measured which is difened by the value of sample size 2-4).For example, it has been both experimentally and theoretically demonstrated that peakprofiles in the small corelation region are corresponded to linear chromatography mechanisms, andwhen the sample size is increased, the non-linear model of chromatography permits accurate prediction of peak profiles the region of big concentrations 5-6). But we consider the same concentration regionthe change of adsorption isotherm parameters leads only to the quantitative changes of the peak profiles characteristics. the particular case is connected with minordeviations of the adsorption isotherm from the linear behavior.It was theoretically shown that a small deviation from the precision expession of adsorption isotherm ( the small deviation from adsorption isotherm linearity) can lead to simulation of the peak profiles which differ significantly each from other in the same concentration region 7-9)The purpose of this article is the experimental confirmation of this effect. The original equationof the LEA model is ordinary firast order differential equation which may be written as da/dt+dc/dt =(ν/Le)/[cB-f^(-1)(a] (1), где a and c are respectively the average solute concentrations in the stationary and mobile phases of column bulk of lenght Le, ν is the mobile phase flow velocity, the layer of equilibrium adsorption Le is an effective kinetic constant, c is the cocentration entering to the layer Le, f^(-1)(a) is concentration issuing from this layer Land also the analytical expression of the adsorption isotherm, and t is the time. In the LEA modelit is proposed which characterize the solute mass transfer kinetics and the longitudinal mass transfer should only be expressed interms of the adsorbent layer length. this method of depicting the kinetic constant, which emp;oysthe principle of the superposition of broadening factors, arises fromthe teory of van Deemter 10) and has beenrepeadly demonstratedon the linear chromatography experiments.So, in the LEA model the constant of the in dividual kinetic stagesare expressed only in terms of a column length scale. By analogy with a definition given for HETP in [10], an effective kinetic constant Le represents the sum of separate termsthat express the constants of the elementary kinetic(mass-transfer) stages, including the longitudinal (axial) dispersion.
- Добавил в систему: Ларин Александр Васильевич